Hi, there was a similar discussion with a ramdisk: http://archives.postgresql.org/pgsql-hackers/2005-11/msg01058.php You need to populate the data on serverstart, of course. But as Timo mentionend, it's maybe not worth the trouble. Maybe their is a way to speed up the queriy itself. To analyze this, you should post the query- and table-definition and the output of explain analyze of the offending query. Best regards Hakan Kocaman Software-Development digame.de GmbH Richard-Byrd-Str. 4-8 50829 Köln Tel.: +49 (0) 221 59 68 88 31 Fax: +49 (0) 221 59 68 88 98 Email: hakan.kocaman@xxxxxxxxx > -----Original Message----- > From: pgsql-performance-owner@xxxxxxxxxxxxxx > [mailto:pgsql-performance-owner@xxxxxxxxxxxxxx] On Behalf Of > Thomas Vatter > Sent: Wednesday, May 10, 2006 12:43 PM > To: Tino Wildenhain > Cc: pgsql-performance@xxxxxxxxxxxxxx > Subject: Re: [PERFORM] in memory views > > > Tino Wildenhain wrote: > > > Thomas Vatter schrieb: > > > >> Tino Wildenhain wrote: > >> > >>> Thomas Vatter schrieb: > >>> > >>>> is there a possibility for creating views or temp tables > in memory > >>>> to avoid disk io when user makes select operations? > >>> > >>> > >>> > >>> > >>> No need. The data will be available in OS and database caches if > >>> they are really required often. If not, tune up the caches and > >>> do a regular "pre select". > >>> > >>> Regards > >>> Tino > >>> > >>> > >> > >> hmm, I am selecting a resultset with 1300 rows joined from > 12 tables. > >> with jdbc I am waiting 40 seconds until the first row appears. The > >> following rows appear really fast but the 40 seconds are a problem. > > > > > > Well you will need the equally 40 seconds to fill your hypothetical > > in memory table. (even a bit more due to the creation of a > > datastructure). > > > > So you can do the aproaches of semi materialized views > (that are in fact > > writing into a shadow table) or just prefetch your data at > time - just > > at the times you would refill your memory tables if they existed. > > A cronjob with select/fetch should do. > > > > Regards > > Tino > > > > > > If the in memory table is created a bootup time of the dbms it is > already present when user selects the data. Of course the > challenge is > to keep the in memory table up to date if data are changed. > What do you > mean with semi materialized views, I have tried select * from > this_view > with the same result. Also, if I repeat the query it does not > run faster. > > regards > tom > > -- > Mit freundlichen Grüßen / Regards > Vatter > > Network Inventory Software > Sun Microsystems Principal Partner > > www.network-inventory.de > Tel. 030-79782510 > E-Mail thomas.vatter@xxxxxxxxxxxxxxxxxxxx > > > ---------------------------(end of > broadcast)--------------------------- > TIP 3: Have you checked our extensive FAQ? > > http://www.postgresql.org/docs/faq >
